Modular spray gun manifold assemblies that include a plurality of laterally spaced spray guns supported in a row for discharging an elongated spray pattern are known. Such manifolds are used, for example, in pill coating machines in the pharmaceutical industry. Spray gun manifolds, such as shown in U.S. Pat. No. 7,083,121 B2 assigned to the same assignee as the present application, the disclosure of which is incorporated herein by reference, comprise spray gun modules disposed between respective support assemblies through which pressurized air and liquid are directed for supplying the plurality of spray gun modules. Liquid directed through the manifold also is recirculated back to the liquid supply.
In some spray applications, it is desirable to monitor the liquid supply to each individual spray gun module in order to detect possible blockage in the spray discharge. For this purpose, it has been necessary to individually supply pressurized liquid to the spray gun modules, rather than through the manifold system, in order to more reliably detect the interruption of discharge of the individual spray gun. While it is also desirable that the liquid be continuously recirculated through the system, when pressurized liquid is individually supplied to the spray gun modules, rather than through the manifold system, this has presented problems.